For decades, the use of ignition locks in motor vehicles has been known, where a locking cylinder receives a suitable key and is rotatable about an axis between an inactive position, a driving position and an intermediate position. In the inactive position, the key can be withdrawn and the engine and all or nearly all electrical components of the vehicle are switched off. In the operating position, the engine and the electrical components are in operation. In the intermediate position, the electrical components are switched on, but the engine is switched off.
In recent years doubts have arisen as to the safety of ignition lock systems, which permit a changeover from the driving position into the intermediate position, while the vehicle is moving. If such a changeover is triggered without the driver's interference, for example, due to the pendulum action of a bunch of keys in the ignition lock, the risk of an accident my be increased.
Therefore, an ignition lock has been proposed, where operational safety is improved, in that a locking cylinder, in the presence of a suitable key, can be shifted along a path between a driving position, in which the ignition lock permits the operation of an engine of the motor vehicle, and a stationary position, in which the operation of the engine is blocked. The path includes a directional change. Even if accidentally and without any interference from the driver, there were forces impacting the key, which might be suitable to move the same along a first section of this path up to the point of the directional change, it would be very unlikely for the same accidental forces to cause the movement of the key also in the changed direction.
There is, however, the problem that drivers of motor vehicles have always been used to bringing the key into the stationary position by continuously rotating it out of the driving position and then withdrawing the key. With a lock of the above-mentioned kind, however, such a rotation is blocked immediately at the point of the directional change. In this position, the engine is not switched off nor can the key be withdrawn, so that a driver not familiar with the ignition lock is inclined to suspect a functional fault. A functional fault which prevents the engine from being switched off and the key from being withdrawn may be very irritating, since the driver would not be able to exit the vehicle and leave it unattended, in order to call help.
Accordingly, there is a need to provide an ignition lock with improved operational safety, where an irritation of even a driver not familiar with this ignition lock can be safely avoided.